Lightwave network data communications system

Abstract

A lightwave network data communications system having such an architecture that routing operation within a lightwave network is simplified, and a high-speed transfer process is attained in a large-scale basic network utilizing a wavelength division multiplexing (WDM) technology which accommodates internet traffics from a plurality of subscriber networks. The lightwave network data communications system includes a unit for giving a lightwave router address to an edge router and a core router in the lightwave network, a unit for resolving a destination lightwave router address and an aggregated flow identifier about an IP packet received from a subscriber, and encapsulating the IP packet into a lightwave adaptation frame with these pieces of data contained in header information in the edge router, a unit for encapsulating a plurality of packets each having a length under a fixed length into a superframe, a unit for executing a share-ride scheme in which the packets of a plurality of IP flows can be shared as a superframe, and a unit for monitoring the traffic on the superframe basis and regulating an excessive traffic.

What is claimed is:  
     
       1. A lightwave network data communications system in a lightwave network accommodating an existing subscriber network, comprising: 
       a lightwave access network for terminating layer  1  to  3  protocols with respect to a protocol of the existing network; and  
       a lightwave core network, connected to said lightwave access network, for terminating the layer  1  protocol and the layer  2  protocol,  
       wherein said lightwave access network converts a user packet of the terminated layer  3  into a lightwave adaptation layer of the layer  2  for transferring the packet matching with a synchronous digital hierarchy using a wavelength division multiplexing technology in the physical layer,  
       wherein said lightwave access network includes a lightwave edge router for converting the user packets coming from the existing subscriber network and transferring the converted user packets to said lightwave core network;  
       said lightwave core network includes a lightwave core router for executing a relay transfer process, and  
       said lightwave edge router and said lightwave core router aggregate the user packets on the basis of QoS information prescribed in a lightwave router address as an address set to the lightwave network transfer and the user packet, and execute an intra-network routing process with respect to each of said lightwave edge router and said lightwave core router,  
       wherein said lightwave edge router accommodates the existing subscriber network, and has a subscriber interface line card for converting a different type of network protocol and a lightwave network interface line card functioning as a connection point to the lightwave network,  
       said lightwave network line card includes a lightwave adaptation frame assembly processing unit for obtaining a destination lightwave router address representing an address of a destination edge router in the lightwave network and an aggregated flow label for managing in aggregation transfer routes for the user packets having the destination addresses from the QoS information and the destination addresses of the user packets received from subscribers, encapsulating the user packets into a lightwave adaptation frame with the lightwave router address and the aggregated flow label contained in header information, and transmitting the lightwave adaptation frame to said lightwave core network.  
     
     
       2. A lightwave network data communications system according to  claim 1 , wherein said lightwave adaptation frame assembly processing unit, as processing memories for executing an interface process with the subscriber network, includes: 
       a lightwave ARP table for resolving the destination lightwave from the destination address received;  
       an AFL table for aggregating a plurality of IP flows corresponding to the destination lightwave router addresses, storing a plurality of aggregated flow labels (AFLs) for routing within the lightwave network and output destination port numbers, and resolving an AFL for a new aggregated flow; and  
       an AFL cache for retaining the output destination port number, the AFL and the lightwave router address for the aggregated flow with the AFL already determined, said AFL cache being referred to for executing a transfer process of subsequent IP packets, and  
       said lightwave adaptation frame assembly processing unit assembles the lightwave adaptation frame by referring to said processing memories.  
     
     
       3. A lightwave network data communications system in a lightwave network accommodating an existing subscriber network, comprising: 
       a lightwave access network for terminating layer  1  to  3  protocols with respect to a protocol of the existing network; and  
       a lightwave core network, connected to said lightwave access network, for terminating the layer  1  protocol and the layer  2  protocol,  
       wherein said lightwave access network converts a user packet of the terminated layer  3  into a lightwave adaptation layer of the layer  2  for transferring the packet matching with a synchronous digital hierarchy using a wavelength division multiplexing technology in the physical layer,  
       wherein said lightwave access network includes a lightwave edge router for converting the user packets coming from the existing subscriber network and transferring the converted user packets to said lightwave core network;  
       said lightwave core network includes a lightwave core router for executing a relay transfer process, and  
       said lightwave edge router and said lightwave core router aggregate the user packets on the basis of QoS information prescribed in a lightwave router address as an address set to the lightwave network transfer and the user packet, and execute an intra-network routing process with respect to each of said lightwave edge router and said lightwave core router,  
       wherein said lightwave edge router has a superframe assembly processing unit for encapsulating, if a data length of the user packet received from the subscriber is over a fixed length, this one packet intact into a single frame as one lightwave adaptation frame and transferring the single frame to a posterior stage, and, if the data length of each of the user packets is less than the fixed length, encapsulating batchwise a plurality of user packets belonging to the same aggregated flow in a data area into a superframe having a large data length and transferring this superframe to the posterior stage.  
     
     
       4. A lightwave network data communications system according to  claim 3 , wherein said superframe assembly processing unit includes: 
       means for extracting AFLs and destination lightwave router addresses of the lightwave adaptation frames inputted, and accumulating them in a superframe assembly oriented memory per AFL;  
       means for encapsulating, if the data accumulated in said superframe assembly oriented memory are large enough to exceed a predetermined prescribed length of the superframe, these pieces of data into one single superframe, then giving a header thereto and outputting the superframe to a posterior stage; and  
       means for monitoring a time-out with respect to the packet data per AFL in the process of being accumulated, and outputting the superframe with an occurrence of the time-out to the posterior stage even if a payload length thereof is under the prescribed length.  
     
     
       5. A lightwave network data communications system according to  claim 4 , wherein said superframe assembly processing unit has said superframe assembly oriented memory and a superframe management oriented memory for controlling an output and an input of the frame, 
       said superframe management oriented memory includes an AF management table for storing an information block number for storing data, a stored data quantity and a time-out value per AF number univocally identified from the AFL and the destination lightwave router address; an output block list for storing blocks for executing an output process of the assembled superframe in an output sequence; and a free block list for storing a list of the blocks stored with no data; and  
       said superframe assembly processing unit reads from said AF management table an information block having an AF number for the received frame, adds the received frame to a data length, if the data length after being added is less than a prescribed length, updates the data length of said AF management table, whereas if the added data length exceeds the prescribed length, creates superframe header information for the relevant information block, adds the superframe header information to said output block list, then initializes an item of the AF number concerned, and adds the block with a completion of the output process to said free block list.  
     
     
       6. A lightwave network data communications system in a lightwave network accommodating an existing subscriber network, comprising: 
       a lightwave access network for terminating layer  1  to  3  protocols with respect to a protocol of the existing network; and  
       a lightwave core network, connected to said lightwave access network, for terminating the layer  1  protocol and the layer  2  protocol,  
       wherein said lightwave access network converts a user packet of the terminated layer  3  into a lightwave adaptation layer of the layer  2  for transferring the packet matching with a synchronous digital hierarchy using a wavelength division multiplexing technology in the physical layer,  
       wherein said lightwave access network includes a lightwave edge router for converting the user packets coming from the existing subscriber network and transferring the converted user packets to said lightwave core network;  
       said lightwave core network includes a lightwave core router for executing a relay transfer process, and  
       said lightwave edge router and said lightwave core router aggregate the user packets on the basis of QoS information prescribed in a lightwave router address as an address set to the lightwave network transfer and the user packet, and execute an intra-network routing process with respect to each of said lightwave edge router and said lightwave core router,  
       wherein said lightwave edge router has a superframe deassembly transfer processing unit for identifying, with respect to the superframe having a lightwave router address addressed to said router itself from the lightwave network, a delimitation and a normality of each of the plurality of user packets stored in the data area by referring to the header of each of the user packets encapsulated in a data field, then deassembling and restoring the superframe into the user packets, determining an output destination port number for an execution of the subscriber interface process for transmission based on the header information of the restored user packets, and executing a transfer process to a relevant subscriber network.  
     
     
       7. A lightwave network data communications system in a lightwave network accommodating an existing subscriber network, comprising: 
       a lightwave access network for terminating layer  1  to  3  protocols with respect to a protocol of the existing network; and  
       a lightwave core network, connected to said lightwave access network, for terminating the layer  1  protocol and the layer  2  protocol,  
       wherein said lightwave access network converts a user packet of the terminated layer  3  into a lightwave adaptation layer of the layer  2  for transferring the packet matching with a synchronous digital hierarchy using a wavelength division multiplexing technology in the physical layer,  
       wherein said lightwave access network includes a lightwave edge router for converting the user packets coming from the existing subscriber network and transferring the converted user packets to said lightwave core network;  
       said lightwave core network includes a lightwave core router for executing a relay transfer process, and  
       said lightwave edge router and said lightwave core router aggregate the user packets on the basis of QoS information prescribed in a lightwave router address as an address set to the lightwave network transfer and the user packet, and execute an intra-network routing process with respect to each of said lightwave edge router and said lightwave core router,  
       wherein said lightwave core router, when receiving a plurality of frames exhibiting a low packet encapsulation efficiency and having aggregated flow information, merges and reassembles pieces of information of the plurality of frames into a new superframe, and transfers this superframe.  
     
     
       8. A lightwave network data communications system according to  claim 7 , wherein said lightwave core router has a lightwave network interface card functioning as a connection point to the lightwave network, and 
       said lightwave network line card includes a superframe assembly processing unit for transferring, if a data length of the superframe received from the lightwave network is over a fixed length, the superframe as it is to a posterior stage, if the data length of the superframe received is less than the fixed length, merging and assembling pieces of data of the plurality of superframes belonging to the same aggregated flow into a new superframe, and transferring this new superframe to the posterior stage.  
     
     
       9. A lightwave network data communications system according to  claim 8 , wherein said lightwave core router includes: 
       means for extracting the frames each having the same destination lightwave router address and AFL from the received frames, and accumulating those frames per AFL in said superframe assembly oriented memory;  
       means for encapsulating, if a quantity of the packet data accumulated exceeds over a prescribed length of the superframe, all pieces of packet data into the same superframe, and outputting the superframe with a header given thereto to the posterior stage; and  
       means for monitoring a time-out with respect to the packet data per AFL in the process of being accumulated, and outputting the superframe with an occurrence of the time-out to the posterior stage even if a payload length thereof is under the prescribed length.  
     
     
       10. A lightwave network data communications system in a lightwave network accommodating an existing subscriber network, comprising: 
       a lightwave access network for terminating layer  1  to  3  protocols with respect to a protocol of the existing network; and  
       a lightwave core network, connected to said lightwave access network, for terminating the layer  1  protocol and the layer  2  protocol,  
       wherein said lightwave access network converts a user packet of the terminated layer  3  into a lightwave adaptation layer of the layer  2  for transferring the packet matching with a synchronous digital hierarchy using a wavelength division multiplexing technology in the physical layer,  
       wherein said lightwave access network includes a lightwave edge router for converting the user packets coming from the existing subscriber network and transferring the converted user packets to said lightwave core network;  
       said lightwave core network includes a lightwave core router for executing a relay transfer process, and  
       said lightwave edge router and said lightwave core router aggregate the user packets on the basis of QoS information prescribed in a lightwave router address as an address set to the lightwave network transfer and the user packet, and execute an intra-network routing process with respect to each of said lightwave edge router and said lightwave core router,  
       wherein said lightwave edge router includes:  
       a lightwave adaptation frame assembly processing unit for obtaining a destination lightwave router address representing an address of a destination edge router in the lightwave network and an aggregated flow label for managing in aggregation transfer routes for the user packets having the destination addresses from the QoS information and the destination addresses of the user packets received from subscribers, encapsulating the user packets into a lightwave adaptation frame with the obtained lightwave router address and the aggregated flow label contained in header information, and transmitting the lightwave adaptation frame to said lightwave core network;  
       a superframe assembly processing unit for encapsulating, if a data length of the user packet received from the subscriber is over a fixed length, this one packet intact into a single frame as one lightwave adaptation frame and transferring the single frame to a posterior stage, and, if the data length of each of the user packets is less than the fixed length, encapsulating batchwise a plurality of user packets belonging to the same aggregated flow in a data area into a superframe having a large data length and transferring this superframe to the posterior stage; and  
       a superframe deassembly transfer processing unit for identifying, with respect to the superframe having a lightwave router address addressed to said router itself from the lightwave network, a delimitation and a normality of each of the plurality of user packets stored in the data area by referring to the header of each of the user packets encapsulated in a data field, then deassembling and restoring the superframe into the user packets, determining an output destination port number for an execution of the subscriber interface process for transmission based on the header information of the restored user packets, and executing a transfer process to a relevant subscriber network.  
     
     
       11. A lightwave network data communications system in a lightwave network accommodating an existing subscriber network, comprising: 
       a lightwave access network for terminating layer  1  to  3  protocols with respect to a protocol of the existing network; and  
       a lightwave core network, connected to said lightwave access network, for terminating the layer  1  protocol and the layer  2  protocol,  
       wherein said lightwave access network converts a user packet of the terminated layer  3  into a lightwave adaptation layer of the layer  2  for transferring the packet matching with a synchronous digital hierarchy using a wavelength division multiplexing technology in the physical layer,  
       wherein said lightwave access network includes a lightwave edge router for converting the user packets coming from the existing subscriber network and transferring the converted user packets to said lightwave core network;  
       said lightwave core network includes a lightwave core router for executing a relay transfer process, and  
       said lightwave edge router and said lightwave core router aggregate the user packets on the basis of QoS information prescribed in a lightwave router address as an address set to the lightwave network transfer and the user packet, and execute an intra-network routing process with respect to each of said lightwave edge router and said lightwave core router,  
       wherein said lightwave core router includes:  
       a superframe assembly processing unit for transferring, if a data length of the superframe received from the lightwave network is over a fixed length, the superframe as it is to a posterior stage, if the data length of the superframe received is less than the fixed length, merging and assembling pieces of data of the plurality of superframes belonging to the same aggregated flow into a new superframe, and transferring this new superframe to the posterior stage,  
       said superframe assembly processing unit having said superframe assembly oriented memory and a superframe management oriented memory for controlling an output and input of the frame,  
       said superframe management oriented memory includes an AF management table for storing an information block number for storing data, a stored data quantity and a time-out value per AF number univocally identified from the AFL and the destination lightwave router address; an output block list for storing blocks for executing an output process of the assembled superframe in an output sequence; and a free block list for storing a list of the blocks stored with no data, and  
       said superframe assembly processing unit reads from said AF management table an information block having an AF number for the received frame, adds the received frame to a data length, if the data length after being added is less than a prescribed length, updates the data length of said AF management table, whereas if the added data length exceeds the prescribed length, creates superframe header information for the relevant information block, adds the superframe header information to said output block list, then initializes an item of the AF number concerned, and adds the block with a completion of the output process to said free block list.